This invention relates to a novel method and apparatus for separating and serially delivering single sheets from a stack of sheets. More particularly, the invention pertains to an apparatus and process for aerodynamically separating and transferring such sheets individually to a work station. The individual sheet may then be accurately positioned at the work station for subsequent operations.
It has been known in the art that sheets may be aerodynamically separated and moved by means of airjets through a predetermined guide path. A cushion of air at different pressures on either side of the sheet provide the requisite lift and drag to bias the sheets to travel in a desired direction. The present invention provides a novel apparatus and improved method for individually separating the worksheet and controlling sheet delivery. The invention accomplishes this by first moving the top sheet of a stack of sheets in a direction opposite to the desired travel direction until a stop guide is reached, and then reversing the direction to the desired travel direction.
In a further embodiment of the invention, the single sheet is delivered to a work station for further manipulation. Such may include exposure as in a copying machine or exposure by means of a beam such as a laser or other light beam or an electron, or other particle beam. The system is particularly suitable for exposure of sheets having a photosensitive material on their surface. In a typical operation, the sheet is delivered from the dispenser to an exposure platen and accurately positioned on the platen by means of iterative or trial and error airjet bursts until a desired position is attained. The platen then moves under the exposure means. After exposure, airjets lift the sheet from the platen and it exits the apparatus. Additional operations such as hole punching, etc. may also be performed on the sheet.